Lamp-dimmer.



H. ALEXANDER.

Witnesses: I I Inventor 45 /4014! 1 a 4% I I v Aflornm.

Patented June 5, 19 17.

HARRY ALEXANDER; 035 NEW YORK. N. Y.

LAMP-DIMMER.

Specification of Letters Eatent.

Patented June 5, 191?.

Application filed March 9, 1915. Serial No. 13,278.

To all whom it may concern:

lle it known that I, HARRY ALEXANDER, a citizen of the United States, and resident of the borough of Manhattan, city, county, and State of New York, have invented a certain new and useful La1npDiinmer, of? which the following is a specification.

The object I have in view is the production of a device for dimming or reducing the amount oflight given oil by an incan descent electric lamp.

The particular objects I have in view are to produce a device of this character which will have few moving parts will be cheap to construct, easy to install and certain to maiii 'nilate.

A "Further object is to produce a device in which the amount of light given oil may be regulated within very narrow limits.

These and further objects will more fully appear from the followingspecification and accom )anying drawings, considered together or separately.

Figure l is a longitudinal section of a lamp support embodying the invention;

Fig. 2 is a side elevation of part of the lamp and base thereol einployml with the support illustrated in Fig. l;

Fin"v E3 is a section on the line 3-3 of Fig. 2;

Fig. -l is a scctionon the line l l oi Fig. 1 with the lamp in position in the support;

Fit. 5 is a longitudinal section partly in elevation, of a modification; the lamp being shown as introduced only part-way into the socket;

Fig. 6 is a similar view of another modification;

Fig. 7 is a plan View of a modified form of resistance coil suitable for use with either of the i'noditieations illustrated in Figs. 5 and (i;

Fig. 8 is a side elevation of the coil shown in Fig. 7;

Fig. 9 is a plan view of a modified resist ance coil;

Fig. 10 is a side elevation of the same; and Fig. 11 is a side elevation of a lamp and liase showing still another modification.

In all views like parts are designated by the same reference characters.

In the drawings,

A represents the lamp and B the lamp support. The lamp is provided with a threaded base 1. The support is provided with a threaded socket 2., In the embodiment oi the invention illustrated in l ig's. l to 4' inclusive. the lamp base terminal 3 is formed oi a high resistance material. ln connection with the parts described is an extensible terminal 4. This will make contact with the lamp terminal 5 when the base partly introduced into the socket. This extensible terminal is preferably made of a coil of elastic. wire somewhat like a. spiral spring so that it will make contact with the lamp terminal irrespective of the position of the base within the socket. The terminal l and socket are connected to the connectors ll for the attachment ol the leading in wires in the usual manner. The support is shown as surroumled by a casing 'Z. The base 'i of the lamp is formed mainly of insulation 8. The terminal 23 as shown in Fig. 2 extends trom the inner part of the base to a point somewhat :uljaccnt to the terminal 5. The terminals for the filament ot the lamp are connected respectively to the terminal 5 and the terminal 3. A lilan'icnltcrmimil is con nectcd to the terminal 13 at a point adjacent to that end of the terminal 't'arthcst removed. from the terminal 5. see Fig.

It is apparent. that upon introducing the lamp within the support to an extent sutlicicnt to secure the base 1 wthin the socket- 2, and when the lamp terminal 5 comes into contactwith the extensible terminal 1- and the socket 2 comes into contact with the base terminal 3, that the lamp filament will be thereby introdu cd into the circuit. As the circuit will include substantially the entire length of the base terminal 53, which is made of high resistance material, the amount of current tlowincthrough the lamp-will be reduced and the filament will not become Fully im'aiulescent. Its the base is introduced farther into the socket byrotating the lamp, the current will be allowed to flow through a shorter length of the base terminal 3. hence more current will pass through the filament and the light will become brighter. The extensible terminal will always be in contact with the lamp terminal 5 irrespective of the depth that the base is intrtaluced into the socket. I hereby secure almost an unlimited number of gradations of light from full brilliancy to the utmost dimness cesired. The pressure of the terminal 4 upon the terminal 5 will prevent the base from accidentally becoming unscrewed from the socket and the lamp Wlll therefore he carried in the support, even if only one or two threads of the base engage with threads in the socket.

In the embodiment of the invention illustrated in Fig. 5, the high resistance material is in the form of a helix 9. The lamp base is of the ordinary kind formed of material of a high degree of conductivity. The helix supported in insulation 10 s0 that the current must necessarily pass through as many turns of the helix as are not in contact with the lamp base. In this embodi ment oi the invention the extensible terminal is shown as carried by the lamp base and is adapted to en 'age with the socket terminal 11. In Fig. 5 these two parts are shown separate for clearness ol' illustration, but it is to be understood that the extensible terminal will always engage with the socket terminal after the base has been introduced into the socket.

In Fig. (3 the helix 12 of high resistance material is carried by the lamp base. This base is formed of insulatin material 13. This figure shows the connection of one terminal of the filament with that portion of the helix which is farthest removed from the base terminal as previously described in connection with the description of Fig. 2

Figs. 7. and 8 show a modification of the invention in which the helix instead of being made of a coil of a single piece of high resistance material is made of alternately arranged high resistance material A and low resistance material 15. These are welded or otherwise secured together. This produces a cheaper construction than that illustrated in the preceding figures of the drawing, but having a smaller 'ange of adjustability.

In the embodiment shown in Figs. 9 and 10 split Washers are used. These are made of alternate high resistance washers 16 and low resistance washers 17. This structure has the same advantages and is subject to the same limitations as that illustrated in Figs. 7 and 8. These washers are adapted to be embedded in insulation as shown in Figs. 5 and 6 and the abutting ends of the adjacent washers may be welded together or may be simply in physical contact.

Fig. 11 illustrates a modification of the invention in which the base of the lamp is formed of a single-piece of high resistance material. This lamp is adapted to be introduced within a socket such as shown in Figs. 1 and 6. One terminal of the filament is connected to the lamp terminal 5 and the other one with the base terminal 18 at a point removed from that end of the lan'ip adjacent to the terminal 5, for example at the point X of Fig. 11.. Such a lamp introduced within the socket shown in Fig. 1 will produce gradations of l' i'; depcnding upon the extent in which it is introduced owing to the amount of the high resistance material introduced in the circuit.

Any suitable n'niterial, for example tin or German silver, may be used for the high resistance material, while copper may be used for the low resistance material when em ployed.

In accordance with the provisions of the patent statutes, 1 have described the principle of my invention, together with the apparatus which I now consider to represent the best embodiment thereof; but I desire to have it understood that the apparatus shown is merely illustrative and that the invention may be carried out in other ways.

Having now described my invention, what I claim as new and desire to secure by Let ters Patent, is:

1. A lamp dimmer, which comprises a threaded base and a threaded socket. one o'i" which includes a material oi high electrical resistance, said base engaging directly with said socket, and an extensible terminal associated with both elements and making contact therebetween irrespective'oit the distance that the base is inserted in the socket.

A lamp dimmer which comprises a threaded base and a threaded socket, one of which is provided with a region of high electrical resistance, said base engaging directly with said socket, and an extensible terminal carried by one element and adapted to make contact with the other element irrespective ot the distance that the base is inserted in the socket.

3. A lamp dimmer which connn'ises a threaded base and a threaded socket, one of which is provided with a. region of high electrical resistance extending longitudinally thereof, said base engaging directly with said socket, and an extensible terminal carried by the socket and adapted to make contact with the base irrespective of the distance that the base is inserted in the socket.

This specification signed and witnessed this eighth day of March, 1915. I

HARRY ALEXANDER.

Witnesses ANNA E. BENTON, LEONARD H. Dyna. 

